Tonight, I tried some different setups between my Recto and a Line 6 Pod X3 Live. I was trying to get a good headphone mix for silent playing. The “Slave Out” was making noise and I switched to using a send from my Nova System to the X3. I found the similarities between the modes to be quite minimal. It was striking, really.

FX Send Out

From the FX Send, Raw mode is not voiced too differently from the others, besides the tighter bass. The volume difference is less extreme and it is more distorted and sharp. This mode, contrasted with the sound of the same settings when taken from a speaker jack, the role of the negative feedback (NFB) is illustrated. It reduces all the harmonics, distortion, and flattens the overall response from 30 Hz to 10 kHz.

Switching to Vintage mode, the volume and bass bumped up a little, but the sound itself didn’t change a whole lot. Vintage has more saturation, but the character was not radically different from Raw.

Modern was very bright. The addition of the Presence pot to the preamp EQ made it sizzle a little more than the others, but the volume was no different from Vintage.

Conventional Use

The point of all this is how NFB affects the power amp. Through a cabinet, Raw drops in volume and distortion in the PI, because the NFB is higher than any other mode. Flip it to Vintage and the volume increases a little, because the NFB is a little less. Vintage is darker, due to the bottom coming up, and the distortion is greater than Raw. It slowly opens up as the Presence is increased, because the NFB decreases and it becomes louder, with more distortion on the top, and brighter at the same time. Flip it to Modern and the volume jumps from the NFB being removed. Along with other considerations, this also makes it the most distorted mode and it is capable of reproducing greater treble and presence ranges in the power amp.

Master of Preamps

When using the Recto as a power amp for another amp slaved into it, the manual recommends Channel 1 Clean to be used for sensitivity and an ability to use the Presence control. This may be an oversight, since much of the manual was not updated from the previous version of Recto.

According to the schematic, Modern and Clean have the same circuit from the FX Return to the cabinet outputs. Both have their Presence controls in the preamp section and neither will affect the power amp directly. It is possible that part of relay 2 was omitted for a section in the power amp, but the Presence should still not function. Vintage would be the only mode to have any use of the Presence control, as its pot actually is in the power circuit.

So, the thought occurred to me, “What if a person were to just switch modes around based on the idea of what particular power amp response they desire?” Clean/Modern would be the loudest, least dynamic, have more mid-range, and possess no filtering of harmonics. Vintage would have the Presence control in the circuit and some dynamics. Raw would be quietest, have the most filtering, and has the most dynamics available.

This consideration is even more important if a person wishes to slave a digital preamp into the FX Return. Since the majority of digital units have problems with dynamics and suffer from tone issues in their treble and presence frequencies, Raw might just be a solution to getting a good feel from this setup. Try it out for yourself and see if it gives you another avenue for creativity. Vintage is also a good idea if a person feels that Raw removes too much from the top or from the distortion.